Steriod Injection

Dear Dr Bland and Emma, it is now two weeks since I had a steroid injection in my right hand. It took nearly one week before I could feel any improvement and by day ten things were really looking better. It is so nice to have a full night's sleep without waking up in pain during the night or early morning. I wear my splint during the night which is a great help and on and off during the day, especially if I am ironing. I am just a little anxious that this won't last. How long do the injections last or does it depend on the severity of CT? Dr Bland, if my symptoms flare up again can I get in contact with you direct or do I have to go through my GP? I do realise there are only so many steroid injections one can have.